PITTSBURGH, Pa. - Backed up deep in their own territory, their slow start to the season in danger of turning into a legitimate freefall, the Pittsburgh Steelers did what they always seem to do when things get tight.

They relaxed.

Ben Roethlisberger converted a pair of critical third downs during a remarkably patient 64-yard drive over the final 6:33 and Shaun Suisham drilled a 34-yard field goal as time expired to lift the Steelers to a 16-14 victory over the Philadelphia Eagles in the rain on Sunday.

It's a way of life the Eagles had grown comfortable with during the season's opening month. Philadelphia (3-2) appeared on the verge of its third one-point win of the season when Michael Vick hit Brent Celek for a 2-yard score midway through the fourth quarter.

The Steelers (2-2) started at their own 20 then promptly went backwards thanks to a holding penalty.

No biggie.

Roethlisberger hit Antonio Brown for 20 yards on third-and-12. A 15-yard screen pass to running back Rashard Mendenhall — making his return from surgery to repair a torn ACL in his right knee — moved Pittsburgh into Eagles territory.

Two plays later Roethlisberger found Emmanuel Sanders for an eight-yard gain and five straight runs put the Steelers well within Suisham's range. The kick was good all the way, and the Steelers avoided their first 1-3 start under Tomlin.

"I always have confidence in myself and the guys that we can do it," said Roethlisberger after engineering his 25th career fourth-quarter comeback. "It's good to go down. That was everybody on that drive."

Roethlisberger completed 21 of 37 passes for 207 yards, and Mendenhall finished with 81 rushing yards and a score while adding 20 receiving yards as Pittsburgh's beleaguered running game showed signs of life.

"Our saviour is back," Roethlisberger joked. "We've been teasing him all week. It was great to see him out there and he did a great job."

Vick completed 20 of 30 passes for 175 yards and two scores but fumbled twice for the Eagles, who couldn't keep their string of narrow early-season victories going. LeSean McCoy rushed for 53 yards, and caught four passes for 27 yards and a touchdown for Philadelphia.

"This one is going to burn for a minute," Vick said.

The Eagles trailed the whole way but put together a grinding 17-play, 79-yard drive at the start of the final quarter, converting a pair of risky fourth downs, including one deep inside their own territory. McCoy turned both into first downs, twisting for the necessary yardage on fourth-and-inches at the Philadelphia 30 then bulling for two yards on fourth-and-1 at the Pittsburgh 47.

"I don't know how I can say this humble ... we felt like we could drive on them," McCoy said.

Scoring, however, proved to be another matter.

"You're going to need to score more points, going to need to help our defence out a lot more," Vick said. "And we tried to the best we can. Pittsburgh's a good football team; their record might not have shown it."

The Steelers came in smarting following a 34-31 loss in Oakland two weeks ago before heading into a well-timed bye that allowed the defence to get healthy. Pittsburgh hoped the return of linebacker James Harrison and safety Troy Polamalu from injury would spark a defence that looked a step slow in in the second half of losses to the Raiders and Broncos.

The reunion of the two stars didn't last long.

Polamalu left in the first quarter after re-aggravating a strained right calf and the Steelers lost outside linebacker LaMarr Woodley with a strained hamstring shortly thereafter.

Still, the Steelers prevented the Eagles from making big plays. Philadelphia's longest gain was all of 24 yards and Pittsburgh forced Vick to fumble three times — including on into the end zone that Steelers linebacker Larry Foote pounced on — and didn't let him get anything going with his legs.

"Our defence stood up today," said Steelers linebacker Lawrence Timmons. "We really needed this win. A good team is always defined by what they do after losses."

The in-state rivals face each other only once every four years, though things were pretty chippy. There was a considerable amount of pushing and shoving after the whistle and flow of any variety was hard to come by on a day the teams combined for 14 penalties, including nine by the Steelers.

Pittsburgh's offence found its footing first, with Mendenhall taking a lateral from Roethlisberger and dashing 13 yards for a score midway through the second quarter.

"When I stepped out there I knew I would be comfortable," said Mendenhall, who hadn't played since injuring the knee in a victory over Cleveland on New Year's Day. "I just wanted to go out there and play the best that I could and I was able to do that."

Pittsburgh made it 10-0 at the half on a 20-yard field goal by Suisham, though the Steelers missed a chance to go up two touchdowns when Jerricho Cotchery tripped going into the end zone.

Philadelphia drew within 10-7 on a 15-yard touchdown pass from Vick to McCoy, setting up a dramatic fourth quarter in which the Steelers turned the tables on the Eagles.

"Things happen," Vick said. "I wish I could take the fumble back on the goal line but you can't. Ultimately I think we put ourselves into a position to win this game and we didn't win."

NOTES: Tomlin said it's too early to tell if either Woodley or Polamalu will be available for Thursday night's game in Tennessee ... The Eagles escaped injury-free according to coach Andy Reid. RB Bryce Brown left briefly with a shoulder strain while LB Mychal Kendricks went out for a bit with a sprained ankle ... The Steelers are 5-1 after bye weeks under Tomlin ... Pittsburgh TE Heath Miller had four receptions for 43 yards to become the eighth player in franchise history to top 4,000 career receiving yards ... Vick had a quarterback rating of 104.2, the 12th time he's topped the 100 mark during his time in Philadelphia ... The Eagles host Detroit next Sunday.